Considered a leading Sovietologist during the 1940s and 1950s, Mandel was a fellow at Stanford University's Hoover Institution, but lost his position there due to the political pressures of the McCarthy era. He is perhaps best known for standing up to Senator Joseph McCarthy during a televised 1953 Senate committee hearing[1] in which Mandel pointedly told the senator, "This is a book-burning! You lack only the tinder to set fire to the books as Hitler did twenty years ago, and I am going to get that across to the American people!"[2]

In 1960, Mandel was again subpoenaed, this time by the House Un-American Activities Committee. He testified on May 13 in a hearing held at the San Francisco City Hall. Outside the hearing, hundreds of protesting Bay Area college students were blasted with firehoses and dragged down the marble steps by police officers, leaving some seriously injured.[3] Newsreel cameras recorded Mandel's scathing response to the question posed by Lead Counsel Richard Arens, "Are you now or have you ever been a member of the Communist Party?":

Honorable beaters of children, sadists, uniformed and in plain clothes, distinguished Dixiecrat wearing the clothing of a gentleman, eminent Republican who opposes an accommodation with the one country with which we must live at peace in order for us and all our children to survive. My boy of fifteen left this room a few minutes ago in sound health and not jailed, solely because I asked him to be in here to learn something about the procedures of the United States government and one of its committees. Had he been outside where a son of a friend of mine had his head split by these goons operating under your orders, my boy today might have paid the penalty of permanent injury or a police record for desiring to come here and hear how this committee operates. If you think that I am going to cooperate with this collection of Judases, of men who sit there in violation of the United States Constitution, if you think I will cooperate with you in any way, you are insane!"[4]

Mandel "spent the remainder of his testimony respectfully telling his inquisitors to go to hell."[5]William F. Buckley later characterized Mandel's testimony as "a histrionic speech."[6]

Recordings of the hearing were aired repeatedly on KPFA and other Pacifica Radio stations in subsequent years, and "literally represented the final hours of the 1950s" for young people who had come of age in the McCarthy era.[5] Scenes from the hearings and protest were later featured in the award-winning 1990 documentary, Berkeley in the Sixties.

Mandel began his career as a broadcaster in 1958, with an hour-long weekly program on Pacifica Radio station KPFA-FM in Berkeley, California. Originally called "Soviet Press and Periodicals", the program stayed on the air under various names until 1995, when it was abruptly cancelled due to internal conflicts at the station. Mandel appears in the documentary film KPFA On the Air (Independent Television Service, 2000). Subsequently, Mandel hosted a weekly show on Free Radio Berkeley.[7]

In his book, In Battle for Peace, the noted Black American scholar and activist Dr. W. E. B. Du Bois referred to William Mandel's "defense" of him when Du Bois was "under federal indictment for heading the circulation of a peace petition".[8]

In 1968, he signed the “Writers and Editors War Tax Protest” pledge, vowing to refuse tax payments in protest against the Vietnam War.[10]

In 1992 he served as the consulting editor to the production of "The Rise and Fall of the Soviet Union Trading Cards: From Lenin to Yeltsin," a history of the USSR in the form of a series of baseball cards, written by David Thorpe and illustrated by Greg Copeland.[11]

The introduction to Mandel's autobiography, Saying No To Power, was written by the left wing historian and author Howard Zinn. The book received critical acclaim from notables, including author and senior editor of The Black Scholar,Robert L. Allen; renowned musician and activist Pete Seeger; and the internationally respected poet Lawrence Ferlinghetti.

^U.S. House of Representatives Committee on Un-American Activities, The Northern California District of the Communist Party: Structure, Objectives, Leadership (Washington, D.C.: U.S. Government Printing Office, 1960), 2066.